Brush rigging



Jan. 30, 1923. 1,443,499

H. S. PARDEE BRUSH Rlccmc. FILED APR. 22. I920- 2 SBEETS'SHEET I 4 z z a IVENTOR.

Jan. 30, 1923.

H. S. PARDEE. BRUSH Russ: NG. FILED APR. 22, 1920 2 SHEETS'SHEET 2 ORNEY Patented Jan. 30, 1923.

ARVEY s. PABDEE, or crrIcAeo, rumors.

BRUSH RIGGING.

Application filed April 22, 1920. Serial No. 375,782.

To all whom it may concern Be it known that I, HARVEY S. PARDEE, a citizen of the United States, and a resident of Chicago, State of Illinois, have invented an Improvement in Brush Rigging, of

which the following is a specification.

This invention relates to electrical apparatus and with regard to certain more specific features, to a brush-holder for a commutating dynamo-electric machine such as a generator or a motor.

Among the several objects of the invention may be noted the provision of a simple and durable brush rigging, the provision of a compact and inexpensive holder for supporting brushes of opposite polarity in proper relative relation, and the provision of structures adapted to be readily removed as a unit from the machine and replaced by another structure, as, for example, when such replacement is needed for purposes of repair or renewal. Other objects will be in part obvious and in part pointed out hereinafter.

The invention accordingly consists of the elements and combinations of elements, features of construction, and arrangement of parts Which will be exemplified in the structure hereinafter described and the scope of the application of which will be indicated in the following claims.

In the accompanying drawings. in which is shown one of various possible embodiments of the invention,

Fig. 1 is an end view of the commutator of a dynamo-electric machine, showing the brush-holder with the brushes in position for operation, and showing certain adjacent port-ions of the dynamo-electric machine in section.

Fig. 2 is a similar view, on an enlarged scale, showingthe brush-holder structure partly in section.

Fig. is a side view on the line 3--3 oi 45 Fig. 2.

Similar reference characters indicate corresponding parts throughout the several views of the drawings.

Referring now more particularly to Fig. 1 of the accompanying drawings, there is illustrated at 1 the so-called end-bell of a dynamo (motor or generator). This endbell is of any suitable construction, and may be carried by the dynamo frame in the usual manner. The end-bell has an opening 3 permitting access to the brush-holder 5. A detachable cover 7 normally encloses the opening 3 when the apparatus is in use. The dynamo shaft is indicated at 9 and the commutator at 11.

The brush-holder 5 is detachably carried on the end-bell 1 by screws 15 passing through lugs 13 (Fig. 2) on said end-bell. The brush-holder may thus be quickly applied to the dynamo, by attaching the two screws 15, and may similarly be readily taken off for any purpose, without taking apart the elements of the holder, and without removing the brushes therefrom.

The brush-holder supports the brushes 17, which are pressed against the commutator 11 by springs 19 adjustably mounted as at 20, upon the holders 23. Pig-tails 91, at tarhed to the brushes in the usual manner, are screwed to the holders by screws 25, which may also be used to retain in position the brush leads (not shown) inserted inthe apertures 27.

The holders 23 are each secured by screws or bolts 29, to. the block 31, which in turn carries the screws 15 above mentioned. In order that the holders 23 may be insulated from each other and from the block 31, the screws 29 are not in electrical contact with the'holders, but bear against small plates 33 and pass through insulating blocks and bushings 35, as shown in the right-hand. half of Fig. 2. Insulation 37 mounted between the adjacent surfaces of the vertical bosses or flanges 39 of the holders, prevents contact between these two parts and at the same time maintains the parts in proper re lation as a unitary structure.

The brushes 17 are placed approximately in line with the radius of the commutator but are. preferably inclined somewhat to said radius, as indicated in Fig. 2; such inclina tion, however, may be "aried widely or dispensed with, without departing from the field or scope of the present imention.

After the parts have been assembledon thevblock 31, this block is turned at its surfaces d on a radius equal to the radius on which the inside surfaces of the lugs 13 are turned. The holes or boxes in which the brushes 1? have a sliding fit are broached 7 through to provide a definite and suitable the block 31 for receiving the screws 15;

This ensures a good initial fit of the brushes on the commutator, and reduces or eliminates the damage done to commutators from sparking, which is particularly objectionable in many machines when under heavy load.

Since the broaching of the brush boxes and the turning of the surfaces 40 are performed by manufacturing methods which admit of practically exact reproduction, and, further, since the inside surfaces of the lugs 13 are turned concentric with the dynamo shaft at a fixed radial distance therefrom, and since the dynamo commutator may readily be turned to a predetermined diameter, it follows that the manufacture of the brush rigging and initial assembly thereof into dynamos permits of accurate fitting of the brushes of any rigging upon any commutator, without requiring skilled adjustment orhand-fitting, and the same holds true in applyin a rigging to a dynamo already in use, when the rigging thereon is removed for such purposes as repair or renewal.

In operation, the rigging is not liable to revolve about a loose stud, as often happens in the case ofbrush-holders that are mount-- ed on studs and clamped thereto; and the excellence of the initial lit is readily maintained throughout the subsequent operation of the dynamo. The, contact surfaces which determinethe positioning of the holders may thus be turned in a lathe at. the same time the bearing is turned, which ensures concentricity of parts and ease in obtaining an accurate predetermined relation of brushes to commutator.

From the above it will be seen that in the apparatus of the present invention the several objects above noted are attained and other advantageous results secured;

- is various-possible embodiments might be made of the above invention and as various changes might be made in the embodiments above set forth, it is to be understood that all matter herein set forth or shown in the increase accompanying drawings is to be interpreted .on said block and having brush boxes, the

rigging as a whole being removablyadapted to fit on a dynamo by securing the block to the dynamo.

2. A brush rigging comprising a block provided with surfaces concentric with the commutator upon which the rigging is to be used and adapted to fit corresponding surfaces on lugs on a dynamo, and holders mounted on said block and having brush boxes shaped toposition brushes therein in proper relation to the commutator and with a sliding fit with respect to the boxes, the rigging as a whole being removably adapted to fit on a dynamo by securing the block to the end-bell of the dynamo.

3. A brush rigging comprising a block pr vided with surfaces concentric with the commutator upon which the rigging is to be used and adapted to fit corresponding surfaces on lugs on a dynamo, holders mounted on said block and having brush boxes adapted to. position brushes therein in proper re lation to the commutator and with .a sliding fit with respect to the boxes, and means connecting said brushes electrically to the respective holders. 1

l. in apparatus of the class described, in combination, a block provided with surfaces concentric with the commutator upon which the rigging is to be used. and adapted to fit corresponding surfaces on a dynamo, a pair of holders mountedon said block and insulated from said block and from each other and having means for positioning brushes in proper relation to the commutator, means connecting said brushes electri- -ally, to the respective holders, means for connecting brush leads to said holders, and

means bearing against the respective brushes to press the brushes against the commutator, the rigging as a whole being removably adapted to fit on adynamo. by securing the block to the end-bell of the dynamo.

5 In apparatus of the class described, in combination, block provided with surfaces turned concentrically with the commutator upon which the rigging isto be used and adapted to fit correspondingly turned surfaces on lugs on the end-bell of a dynamo, a pair of holders mounted on said block and insulated from said block and from each other and having brush boxes broached to position brushes therein in proper relation to the commutator and with sliding fit withrespect to the boxes, means connecting dynamo by securing the block to the end-bell of the dynamo.

In testimony whereof, I have signed my 10 name to this s April, 1920.

pecification this 17th day of HARVEY S. PARDEE. 

